• Newly designed wireless system uses 2-way radio wave communication for enhanced communication among master and slave units..
• Achieves a transmission distance of up to 98.4 ft. / 30m, all at a 360 degree angle..
• Up to 5 groups, or 15 individual flashes can be controlled via 1 transmitter; 8 types of custom functions, 3 types of personal functions..
• Supports E-TTL II flash, manual flash, strobe and external flash metering..
• Dot matrix LCD panel displays all pertinent information simultaneously and backlit control panel means easy operation. It even features an internal sound emitter..

Product Description ------------------- Newly-designed wireless system uses 2-way radio wave communication for enhanced communication among master and slave units. Achieves a transmission distance of up to 98.4' (30 m), all at a 360 degree angle. Up to 5 groups, or 15 individual flashes can be controlled via 1 transmitter. Supports E-TTL II flash, manual flash, stroboscopic and auto external flash metering. Dot matrix LCD panel displays all pertinent information simultaneously and backlit control panel means easy operation. 8 types of custom functions, 3 types of personal functions. Improved hot shoe contacts for more reliable information transmission and operation. Slave operation confirmation: Green Light--Lit: Radio Transmissions Okay Red Light--Lit: Not Connected Blinking: Transmission Error/ Too many units (Master units + slave units = more than 16 units) Orange Light--Lit: Sub-master transmission Blinking: Receiving remote release shooting, linked shooting signal Not compatible with earlier Speedlite models such as 580EX II From the Manufacturer --------------------- Speedlite Transmitter ST-E3-RT ------------------------------ For sophisticated wireless flash setups, there's nothing like the new Speedlite Transmitter ST-E3-RT*. Facilitating radio controlled, two-way wireless transmission up to 98.4 feet, among up to five groups or fifteen individual Speedlites, the ST-E3-RT represents the next generation in wireless flash systems. With operational controls similar to the new Speedlite 600EX-RT, including diverse flash metering options, and a number of flash modes, the Speedlite Transmitter ST-E3-RT makes complex lighting setups simple. With a compact design and highly reliable construction, combined with a clearly laid-out information panel and buttons with back lighting and more, the Speedlite Transmitter ST-E3-RT is an indispensible tool for advanced, professional flash photography. *Because it does not have an optical transmission function, the Speedlite Transmitter ST-E3-RT is not compatible with earlier Speedlite models such as 580EX II. Newly designed wireless system uses 2-way radio wave communication for enhanced communication among master and slave units. Achieves a transmission distance of up to 98.4 ft./30 m, all at a 360 degree angle. ----------------------------------------------------------------- The Speedlite Transmitter ST-E3-RT facilitates radio controlled, two-way wireless transmission up to 98.4 feet, for a reliable and robust connection among master and slave units. Communicating on 2.4 GHz frequencies, the Speedlite Transmitter ST-E3-RT does not have the same directional limitations of traditional wireless optical transmitters. Where other wireless signals can be interrupted by physical obstacles, radio controlled systems excel. Fifteen transmission channels are available, selectable manually or automatically, and radio transmission IDs can be set to prevent misfiring in the event of signal interference on the same channel. With the extended, more reliable range afforded by radio transmission, ambitious photography is made easier. Up to 5 groups, or 15 individual flashes can be controlled via 1 transmitter. ----------------------------------------------------------------- With the Speedlite Transmitter ST-E3-RT, up to fifteen flashes in five groups can be controlled via a single unit. Each group can be set to a different flash mode, enabling multiple configurations for creative photography. For example, with the Speedlite Transmitter ST-E3-RT, some flashes can be directed to operate according to the cameras meter reading, others can be set manually; groups can be set to overexposure or underexpose, and much, much more. With up to fifteen flashes under the control of one transmitter, wirelessly, complex lighting setups normally reserved for the studio are a breeze. Supports E-TTL II flash, manual flash, stroboscopic and auto external flash metering. ----------------------------------------------------------------- For any number of shooting styles, the Speedlite Transmitter ST-E3-RT supports E-TTL II flash metering, manual flash (1/1 to 1/128) and stroboscopic flash (1/4 to 1/128, 1 to 500 Hz). Auto external flash metering is even possible when the Speedlite Transmitter ST-E3-RT is ed to the EOS-1D X or the EOS 5D Mark III. Dot matrix LCD panel displays all pertinent information simultaneously and backlit control panel means easy operation. ----------------------------------------------------------------- The Speedlite Transmitter ST-E3-RT features an all-new dot matrix LCD panel (172 x 104 dots). This new LCD displays Flash status, flash settings and wireless configuration with more detailed information in comparison to previous systems. With its new screen combined with backlit operation buttons and even an internal sound emitter, the Speedlite Transmitter ST-E3-RT is as easy to operate in the dark as in daylight. 8 types of custom functions, 3 types of personal functions. ----------------------------------------------------------- To accommodate the demands of a number of different shooting situations, the Speedlite Transmitter ST-E3-RT can be configured with eight types of custom and three types of personal functions. Custom functions include: auto power off, modeling flash controls, sound, illumination and more. Personal functions include display contrast and LCD panel illumination color for both master and slave flashes. Improved hot shoe contacts for more reliable information transmission and operation; compact design is approx. 2.65 (w) x 2.42 (H) x 3.05 (D) in. ----------------------------------------------------------------- The Speedlite Transmitter ST-E3-RT is built to the standards one would expect from professional Canon camera systems. A newly updated hot shoe contact ensures reliable communication between camera and transmitter. Dust and water resistance is excellent as well: all moving parts and areas surrounding the transmitters display and buttons are sealed for uninterrupted performance in harsh conditions. A new dust and water resistant adapter for the ing foot creates a dust and water resistant seal between camera and flash. Compact and lightweight, the Speedlite Transmitter ST-E3-RT is approx. 2.65 (w) x 2.42 (H) x 3.05 (D) in.